Nest predation in hole‐nesting birds in relation to habitat edge: an experiment

We experimentally tested the hypothesis that nest predation rate in hole‐nesting birds, especially the common goldeneye Bucephala clangula , was related to the edge between aquatic and terrestrial habitats We also studied whether nest predation rate was related to habitat patch (lake) size In three study areas nest‐boxes were erected in pairs one nest‐box was erected at the shoreline and the other one inside the forest at a varying distance (range from 14 to 140 m) from the shoreline One chicken egg was placed in each nest‐box (dummy nest) Overall predation rate on dummy nests varied from 34 6% to 52 6% depending on the study area The pine marten Martes manes was the primary nest predator m all study areas Daily predation rates did not differ between natural and dummy nests Predation rate on dummy nests was not related to the distance of the nest‐box from the shoreline in any study area Predation rate was not related to lake size in two study areas but in one area predation rate on dummy nests was lower around largest lakes However, the result may be accidental and not because of lake size per se because the proportion of forest was exceptionally low in that part of the study area